Various kinds of insulators attached to a core of an electric motor, and the like, have been proposed. For example, an insulator disclosed in JP2003-61287A is made of insulating resin material and includes a main body portion and multiple extending portions. The main body portion axially covers one side face of a core that includes multiple teeth portions extending in a radial direction. The extending portions extend from the main body portion in parallel with an axis of the core so as to cover multiple slots that are formed respectively between the teeth portions adjacent to each other. A pair of such insulators are attached axially to the core from both sides respectively, for mainly ensuring insulation between the core and a winding wire.
The core of the electric motor, and the like has a complicated structure of multiple teeth portions (or multiple slots), which may cause difficulty in attaching the resin-molded insulator to the core. This is because all of the multiple extending portions that may slightly vary in shape are required to make simultaneously contact with the slots respectively for positioning when the insulator is assembled on the core.
Thus, a need exists for an insulator that can provide improved assembly performance relative to a core.